As wireless charging adoption continues to show double-digit annual growth rates, industry pundits have openly wondered when Apple's iPhone would finally take the plunge.

This month, market research firm IHS predicted that Apple would introduce some form of wireless charging on the iPhone 7 expected to arrive in September; that move seems more likely given that Apple introduced an inductive, proprietary charging solution in 2015 on the Apple Watch.

Adding fuel to the wireless charging fire, Bloomberg today reported that Apple is working with partners in the U.S. and Asia to develop new wireless charging technology that could be deployed on its mobile devices in 2017.

"We still expect [wireless charging with the iPhone 7], but this latest rumor suggests a longer term look at much greater spatial freedom — claiming to take away the charging pad altogether," David Green, a research manager at IHS Technology, said in a report today.

Apple's CarPlay allows the iPhone to mirror itself to a car's infotainment system.

Wireless charging is proving to be very popular with those who have used it, and the market tripled in size last year compared to 2014, with more than 160 million wireless charging receivers shipped across all markets.

The three major wireless charging industry groups have adopted a form of resonant wireless charging, which allows a more "loosely coupled" approach where handsets can be several centimeters away from a charger or placed at any angle on a charging pad.

For example, AirFuel Alliance's Rezence-specification, which allows charging from across several centimeters, includes the ability to use a charging bowl or charging through a desktop.

There's also uncoupled charging technology, where powering up devices through Wi-Fi, for example, sends low levels of power (typically less than 1 watt) across a room.

Loosely coupled charging — and the Rezence-specification, in particular — are expected to launch into commercial availability this year, possibly as early as Mobile World Congress (MWC) in February, Green said. Uncoupled technology, however, is likely to take longer to reach the mass market.

At least one handset manufacturer partnership with an uncoupled charging technology company is expected announce this year, Green added. But commercial availability by September 2017 would be the earliest expected commercial launch.

In a poll conducted earlier this month by IHS, 90% of respondents indicated they would choose wireless charging technology on their next handset.

In December, market research firm Technavio predicted the global wireless charging market would have a combined annual grow rate of more than 33% by 2020.

"The integration of wireless charging for smartphones in automobiles will drive market growth," Technavio stated in its report.

As Apple's in-vehicle infotainmment API, CarPlay, continues to gain adoption among major automakers — allowing iPhone apps and functions to be mirrored to a radio head unit — allowing the handset to charge at the same time only make sense.

Last August, Juniper Research released a study that found wireless charging adoption for mobile devices will increase rapidly in the coming years, with nearly 40% of households in the U.S. and over 20% in Europe using wireless charging by 2020.

"It remains to be seen which option Apple could be looking at for the iPhone, regardless of whether they will go for industry-standard certified or a proprietary solution," Green said.